Within endoscopic surgery, there is a recognized need for simple devices such as graspers, dissectors, scissors, and other basic surgical instruments. These instruments are necessary in order to perform simple functions during the endoscopic procedure. Specifically, devices such as graspers are necessary in order to properly move the work site away from the other vital organs so that the tissue to be worked on may be isolated and surgery may be performed. Scissors may be needed in order to make an appropriate cut in tissue, muscle or other vasculature. Dissectors can be necessary to separate one portion of tissue from another. These instruments also enable the other, larger instruments such as staplers and ligating clip appliers to have enough volumetric room in order to perform operations such as appendectomies, cholecystectomies, herniorrhaphies, etc.
Traditionally, instruments such as graspers, dissectors, scissors and other endoscopic instruments have been mounted on generally straight shafts. These shafts may or may not have been able to rotate about the longitudinal axis of the shaft. Nonetheless, there has been perceived a need for the end effector of the shaft to be able to angulate with respect to the longitudinal axis of the shaft. This may enable the surgeon to attack the tissue which is to be operated from an oblique angle. In fact, it may be desirable to have the shaft angulate up to 90.degree. with respect to the longitudinal axis of the shaft. In many ways, this function can be analogized to the capability of the human hand to rotate around the "axis" of the arm, and also "angulate" about the wrist. Of course, while the hand is able to function with pure rotation, the degrees of freedom given by wrist action are much greater and in many ways enhance the ability of the hand to perform simple daily functions. Thus, there is perceived a need for an articulating, angulating endoscopic instrument so that the functions of such mechanisms can be made much more versatile.
Previously, there have been attempts at creating articulating instruments but none of these instruments have the capability of performing functions at an angulation of 90.degree. to the longitudinal shaft of the endoscopic mechanism. This is due, in large part, to the tolerancing and material strength problems encountered by the manufacturers of such instruments. It must be remembered that it is necessary to not only have an instrument which can create such angulations, but it also be capable of operating the end effectors at such angulations. This combination has been difficult to create, and has caused design sacrifices to be made. Generally, these sacrifices have been made to the versatility of such instruments, so that such endoscopic instruments are not capable of being angulated at 90.degree. to the shaft of the instrument. Of course, with this restrictive limitation, the ultimate capabilities of such angulations are not met.
Furthermore, there has been realized a need to maintain the end effectors of the device in a particularly preferred position. Generally, the device maintains such a position via use of a ratchet mechanism placed in the handle of the device. However, these ratchet mechanisms may be hard to manipulate at times, or, in some instances may be in the way of the user's fingers, depending on the position of the ratchet. In either event, the use of such a ratchet is seen as a less than optimal solution to the problem of maintaining the end effectors in their desired position.